When a semiconductor manufacturing apparatus is operated for a long time, the reproducibility of the process decreases due to various factors such as, for example, wear and deterioration of components, change in the internal environment of the chamber due to the accumulation of by-products generated from the process, change in utility environment of, for example, gas and cooling water to be supplied, and sudden breakdown of components. The frequency of occurrence of the events varies depending on the operation state of the apparatus, and the occurrence of the events may be easily predicted or not.
In the case where the occurrence of the events is easily predicted, it is possible to preventively and conservatively cope with the events by performing replacement or adjustment of consumable parts by periodical maintenance. Meanwhile, in the case where the occurrence of the events is not easily predicted, it is difficult to cope with the events by the periodical maintenance.
Therefore, in the related art, long-term trends are monitored by converting output values output by various sensors during the performance of the process into representative values (e.g., an average value, a maximum value, and a minimum value) in a predetermined period, for example, in step units included in the process, and using the representative values (see, e.g., Japanese Patent Laid-Open Publication No. 2015-037086).